1. Field of the Invention
The present invention relates to an optical pickup, and more particularly, to an optical pickup which can reduce the generation of noise due to interference of light reflected by a recording medium and reentering a laser light source, and a polarization changer suitable for the optical pickup.
2. Description of the Related Art
In general, an optical recording and/or reproducing apparatus using an optical pickup records by focusing a laser light used as a light source emitted from a laser diode that is used as a light source on a recording medium (i.e., an optical disc) by using an objective lens. During reproduction, the optical recording and/or reproducing apparatus detects information signals recorded on the optical disc by receiving light reflected by the optical disc and converting the light to electric signals.
The light reflected by the optical disc during recording or reproduction generates noise due to the interference of the light emitted from the laser diode at a light emitting point as the reflected light reenters the laser diode. Since a high optical power is needed for a high multiple speed, the noise increases. Thus, for high multiple speed, the light reflected by the optical disc which generates noise must be reduced.